Predicting when volcanic eruptions will occur is one of those things we just don’t do well, yet. Currently, I’m stanning the Icelandic Meteorological Office and its “is it / isn’t it” coverage of a possible upcoming eruption on the Reykjanes peninsula, just far enough away from Reykjavik to make things interesting but not dangerous. For a while there, it looked like things were going to blow, but we’re now seeing things calm down and while alerts remain in place, the situation is being reassessed with an update due after the time of this recording [Ed. note: Fagradalsfjall erupted on Friday, 19 March].

To try and understand when we need to worry and when we can ignore rumbling mountains, geologists are turning to thermal data. 

In new research appearing in Nature Geoscience, Társilo Girona and colleagues present a 3.5-year analysis of the temperatures around various volcanoes before they erupted. Ninety percent of these eruptions weren’t predicted, but Girona discovered in historic data that the ground temperatures around the volcanoes increased by one degree Celcius in the years leading up to the eruptions. This doesn’t tell us exactly when an eruption is coming, but it does spotlight which mountains are worth worrying about. 

The land isn’t heated directly by the magma. Rather the rising magma releases huge amounts of water vapor, carbon dioxide, and sulfur dioxide gas that transfers heat while in some cases vaporizing groundwater. The heat released by these gases and vapors heats the land as it cools and escapes. According to  Florian Schwandner, deputy chief of the NASA Ames Earth Science Division: Girona’s research has shown that satellite data can be used to detect a volcano heating up years before an eruption—we didn’t know that before.

Hopefully, this kind of information will make it easier to forecast places not as volcanically covered as Iceland, which I will continue to stan in hopes of a harmless but pretty eruption.

More Information

Eos article

“Large-scale thermal unrest of volcanoes for years prior to eruption,” Társilo Girona, Vincent Realmuto, and Paul Lundgren, 2021 March 11, Nature Geoscience